The present disclosure relates to polarizer protective sheets and polarizers, which are used in liquid crystal display (LCD) devices, and LCD devices.
In recent years, flat displays such as LCDs and plasma displays have been widely used as display devices due to their space-saving design and high definition quality. Among others, the LCDs have attracted much attention and have been actively developed due to their power-saving features and high definition quality.
The LCDs are non-emitting display devices including, e.g., an LCD panel formed by a thin film transistor (TFT) substrate and a color filter (CF) substrate which are disposed so as to face each other and a liquid crystal layer enclosed between the TFT substrate and the CF substrate, and a backlight disposed on the back side of the LCD panel. The CF substrate has colored layers of, e.g., red, green, and blue for subpixels that form pixels.
In the LCD panel, polarizers that serve as a light shutter are combined with liquid crystal. The polarizer includes a polarizing element. Since polarizing elements are typically produced by uniaxially stretching a polyvinyl alcohol resin to five to six times its original length in a water tank, the polarizing elements are brittle and easily torn in the stretching direction. A protective film is therefore bonded to the front and/or back surface of the polarizing element.
In recent years, LCD devices using a functional film having multiple functions have been proposed in order to meet the demand for smaller devices. More specifically, for example, an LCD device is disclosed which includes a polarizer protective sheet formed by melt-extruding a thermoplastic resin from a molding die into a sheet and forming a concavo-convex pattern on one surface of the thermoplastic resin sheet (see, e.g., Japanese Unexamined Patent Publication No. 2015-40978).